1. Field of the Invention
The present invention relates to interlocking building blocks for constructing a building or wall.
It is common practice to erect walls using concrete blocks of rectangular configuration with each block having a plurality of cavities and planar on all six sides. The blocks are laid up in courses by placing mortar, by a trowel on the top of the blocks and then positioning the blocks of the next course in the mortar. Forming walls in this manner requires skilled craftsmen trained in the technique of laying concrete blocks to form a wall of predetermined height which is horizontally and vertically true and with the required strength to support an additional floor, roof, or the like.
This invention provides a wall forming series of building blocks which may be laid up by relatively unskilled workmen thus reducing the cost of building erection.
2. Description of the Prior Art
Prior patents generally disclose longitudinally or transversely extending webs usually formed on the upper surface of the building blocks which are nested by cooperating recesses or grooves formed in the depending surface of an overlying block.
The most pertinent prior patent is believed to be U.S. Pat. No. 979,913 which discloses a generally rectangular building block having vertical openings therethrough with each opening surrounded by an upstanding ledge nested by a recess formed in the depending surface of the next overlying block. The blocks of this patent are further provided on a side or end edge thereof with a mortise and tenon for interlocking abutting wall surfaces of the blocks against lateral movement.
This invention similarly uses a tongue and groove arrangement for interlocking the over and underlying blocks but is distinctive over the above named patent by providing a complete line of blocks forming a building structure including blocks having nailable end members for framing a wall opening, longitudinal lateral grooves in the block sides for receiving furring strips, supporting electrical outlet boxes, connecting plumbing fittings thereto and increasing the rigidity of the wall by vertical columns of concrete.